Intelligent toner saving for color printing

ABSTRACT

A software-controlled method for minimizing color toner use during printing of a color page by a color printer including (a) examining the image data for such a page to identify different pre-selected categories of page-contained image elements, (b) associating, with identified different-categories of such elements, specific, respective, pre-determined color-toner usage rules, and (c) following the associating step, outputting the elements to the printer along with instructions that the printer use, in the printing of such elements, the correct, respectively associated color-toner usage rule(s). From a structural point of view, the invention includes examining structure, associating structure, and output structure designed to perform the basic core methodology steps of the invention.

BACKGROUND AND SUMMARY OF THE INVENTION

This invention pertains to an intelligent, software-based system andmethodology for minimizing the use of color toner during color printing.

Color printing is intrinsically more expensive than black-and-whiteprinting. The most expensive component in color printing usually is thecolor toner or ink used to produce the desired color output. Originals,such as photographs, or presentation slides with color backgrounds,require a great deal of color toner. Therefore, these kinds of imagematerials are expensive to print and reproduce.

Recognizing this, many system administrators and IT (informationtechnology) managers restrict the use of color in printed documents. Themost common means to limit color-toner usage takes the form of a simpledirective or policy which is communicated verbally to prospective colorprinter users. For example, an e-mail from management, or a sign postedon a particular color printer, will remind users that color printing ofnon-essential materials is prohibited or restricted. In the extreme,only certain users might be permitted to produce color prints in aparticular color-printing setting.

There are many prior art methods traditionally employed to controlprinting costs through minimizing toner usage, but each comes withdrawbacks. One such method involves using a conventional “toner save”feature commonly seen in printer drivers under functional names such as“black-and-white-lock”, “color saver”, “toner save”, and “draft mode”.These functions frequently rely on simplistic techniques, such asprinting every other pixel, and this approach usually results in verylight images that are often unsatisfactory. Small, thin, or light textand lines can become unreadable.

Another manner sometimes proposed to limit the use of color tonerinvolves providing only monochrome printer drivers to some users. Thisapproach limits the use of color to certain color-critical users. Aproblem with this approach, however, is that color usage is tied to aspecific PC rather than a user or print job. A color-qualified user mayuse a desktop PC to create and proof a job in color, but the same user(or another user) may be unable to print that job from another PCbecause that other computer lacks the required color driver. Anotherproblem with this approach is that monochrome printing on a colorprinter may actually be more expensive than monochrome printing in termsof toner usage.

Still another toner-saving practice involves limiting color printing byrequesting that users print drafts in monochrome, and reserve color forfinal output. However, a key problem with this approach is that theuser's choice is typically either “full color” or “black-and whiteonly”, and color is often important, and as much a part of the creativedocument-producing process as is the creating of text and other objectsthat are normally printed in black-and white. Indeed, in the case ofcolor charts and graphs, color, per se, is the content, and therefore,this either/or approach is not very satisfactory.

There are, of course, numerous other prior art toner-saving practiceswith which those skilled in the art are familiar—each of which otherpractices is known to have its own, particular, noticeable drawbacks.

Thus there is a need for a more intelligent approach that enables usersto limit color-toner usage on a page, but which still preservesimportant information, such as textual and graphical information. Forexample, the colored background in a PowerPoint® presentation adds verylittle to the information content of the presentation. However, thebackground in such a presentation typically uses much more toner thanany other page image element. In this setting, it would be very usefulto permit printing of a presentation, preserving the text and line art,but removing the extensive color-toner-usage background.

The present invention, as will be seen, proposes a software system andmethodology which is useable effectively by a color printer to reducecost by limiting color-toner usage, in a page-by-page manner, indifferent ways regarding different categories of page image elementshaving different information densities. As general illustrations, blacktoner (or no toner) could be used for document page image elements, suchas backgrounds and certain photographs, possessing sparse informationcontent. Alternatively, varying, or differential, amounts of color tonermay be used for information-sparse page image elements.Information-dense page image elements, such as text, could be output ina clearly readable condition, but in a manner using substantially lessthan a “normal amount” of color toner.

In one form of practicing of the present invention, a user is enabledmanually to select various software-implemented, output-processingoptions in a color printing situation, based upon observed page imageelement content categories, and by pre-deciding about appropriate levelsof color-toner usage which should be related to pre-selected choicesmade about related categories of image-content output. For example,employing an appropriate color-printer user interface, i.e., a printerdriver interface, a user can make a determination about (a) how pageimage elements which are characterized by dense information contentshould be output for printing, (b) how page image elements characterizedby sparse information content should be output for printing, and (c) howpage image elements of undetermined information-content density shouldbe output for printing.

These three, preferably utilized “levels” of image-element contentdensity information characteristics, or information content, referred toherein as dense, sparse and unknown, may be determined in various ways.For example, such information content density may be determined (1) bythresholding factors, including local contrast and image entropy, (2) byobject-analysis factors/natures including (a) text, (b) graph, (c) line,(d) photograph, (e) color, (f) size, (g) local contrast, and (h)layering, (3) by page classification factors, (a) page layout, (b)halftone type and frequency, (c) page background complexity, and (d)relative page percentage of various object types, including text,photographs, charts, lines, and colors, and/or (4) by utilizingconventional page-classification factors, including (a) page layout, (b)halftone type and frequency, (c) page background complexity, and (d)relative page percentage of various object types, including text,photographs, charts, lines, and colors. Such determinations may beperformed in a number of different, conventional ways, and thus are notelaborated herein.

In another approach, rather than a user being offered such a manualinput choice, that user could be presented effectively with apre-established, automatically operating software control programimplemented by a system administrator (referred to herein asadministrator-control software), which control program has beenpre-armed with color-toner usage rules that are automatically appliedwith respect to different pre-selected categories of page imageelements. Such elements could be identified automatically, for example,by an appropriate, conventional, software-controlled page-scanningoperation, and then “reviewed” by the use of also conventionalpage-element characterization software. The automatically operatingsoftware control program of this invention could enforceadministrator-applied (administrator-control) corporate polices on user,group, and/or organization levels. Toner-usage rules could beselectively applied using authentication methods, user login, smartcards, biometrics and/or other methods common in the art.

Additionally, in certain forms of “administrator-control”, or“administrator pre-control”, cases, it is possible, and it may bedesirable, under an established toner-usage policy which has been setforth by the administrator, to allow certainusers/groups/organization-levels a particular sub-range, or selection,of toner-usage choices which are outside of strict administratorcontrol. For example, upon user authentication, a selected user could bepresented, as by information provided on a suitable user interface, witha defined range of toner-usage choices, with notification alsoeffectively being simultaneously provided to the user indicating thatcertain toner-usage options are prohibited by the current toner-usagepolicy. As a illustration, options which are prohibited by that policymay be disabled (grayed-out) or simply not presented to the particularuser.

These and other ways of intelligently managing and minimizing the usageof color toner form the focus of the present invention. The inventionthus effectively implements a software methodology, in association withappropriate implementing structure, to enable either a user, or apre-determined software control program, to select and apply appropriatepre-selected color-toner usage rules that become employed in a finaloutput printing operation, based upon a linking of these rules with theresults of a pre-examination of a particular color-page's content ofdifferent-information-density image elements. The features of theinvention, such as those just generally suggested above, and itsadvantages, will now become more fully apparent as the detaileddescription which follows is read in conjunction with the accompanyingdrawings.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block/schematic diagram which illustrates both the uniquemethodology, and the associated structure for implementing thatmethodology, of the present invention with respect to the intelligentsaving of color toner in a color-printing environment.

FIG. 2 presents a representative toner-usage matrix that outlines oneillustrated toner-saving approach, in accordance with practice of thepresent invention, and describing how to apply different pre-selectedcolor-toner usage rules in relation to different, identified,pre-selected categories of image elements which form part of the contentof a color page which is created for printing.

FIG. 3A pictures one representative form of a color-printer-driver userinterface which enables direct user manual inputting of toner-usageinstructions.

FIG. 3B illustrates another form—a slider form—of such an interface.

FIG. 4 shows a representative color page having a relatively widevariety of different, illustrative page image elements to whichcolor-toner usage rules are to be applied in accordance with practice ofthe present invention.

FIG. 5 illustrates the same page of information shown in FIG. 4 afteroutput printing has been performed in the context of the application ofcolor-toner-saving usage rules variously to the different page imageelements which are present in the page shown in FIG. 4.

FIG. 6 is a block/schematic diagram which largely self-explains theoperation of the invention as it relates to the color page contentspictured in FIGS. 4 and 5.

FIGS. 7 and 8 respectively illustrate two, different, self-explanatoryprinting environments designed to implement the practice of the presentinvention. These different environments are more fully described indiscussions about them presented below.

DETAILED DESCRIPTION OF THE INVENTION

Turning attention now to the drawings, and referring first of all toFIG. 1, indicated generally at 10 is a block/schematic diagram whichfully illustrates both the system and the methodology of the presentinvention. In point of fact, this figure, when read in conjunction withdescriptive material which now follows regarding the system andmethodology of the invention, presents these two, principal aspects ofthe invention in a fashion which will fully enable someone generallyskilled in the relevant art to practice this invention.

In particular, FIG. 1 illustrates nine, interconnected, word-labeledblocks 12, 14, 16, 18, 20, 22, 24, 26, 28. Arrowheads which appear onlines that interconnect these blocks in different ways generallyillustrate the flow of information and control which takes place in thesystem and methodology illustrated in FIG. 1.

Implementation and practice of the present invention essentially beginswith the pre-selecting of different categories of image elements, orobjects, which are expected to appear on color pages presented forcopying. These elements are preferably pre-chosen on the basis ofdifferent image content density information characteristics, and anexcellent practice has been found to involve a choice of three differentlevels of information density, referred to herein (as mentioned brieflyabove) as (a) dense, (b) sparse, and (c) unknown. These levels may bedetermined in many different manners, as generally suggested earlierherein, including (1) using thresholding factors, such as local contrastand image entropy, (2) employing object-analysis factors and natures,such as text, graph, line, photograph, color, size, local contrast, andlayering, (3) focusing on page classification factors, such as (a) pagelayout, (b) halftone type and frequency, (c) page background complexity,and (d) relative page percentage of various object types, includingtext, photographs, charts, lines, and colors, and/or (4) utilizingconventionally understood page-classification factors, including (a)page layout, (b) halftone type and frequency, (c) page backgroundcomplexity, and (d) relative page percentage of various object types,including text, photographs, charts, lines, and colors.

The invention also recognizes that a particular type of page imageelement, or object, may not always carry the same kind of informationdensity, depending on the type (classification) of page it is on, orwhat other page objects are present. Therefore, page-classificationfactors may also be considered to be page image elements within thecontemplation of the present invention, and be considered to beimportant in determining information density, and how to employ that“density” concept. For example, page background color may be elected tobe dropped in a PowerPoint® presentation document page, whereasbackground color used to highlight a paragraph in a particular businessdocument may be elected to be preserved.

Conventional, specific “ways” of implementing these characterizingfactors, including ways of employing page-classification factors asrelevant page image elements, are well known in the art, form noparticular part of the present invention, and thus are not discussed indetail herein.

It is with respect to these identified, pre-selected information densitycharacteristics that what are referred to herein as color-toner usagerules are established to define how toner will be employed during colorprinting to deal, respectively, with each of these categoricalcharacteristics.

It should be understood that while a particular, illustrative hierarchyof image content density characteristics is specifically presented anddescribed herein, this hierarchy, or “plan”, for the establishment oftoner-usage rules is intended to be illustrative only, and not in anysense limiting with respect to the granularity of image content densitycharacteristics which may freely be chosen by one determined toimplement and practice the present invention. It is the use ofdifferentiated image content information density which furnishes centralpower to the intelligent and efficient use of color toner in thepractice of the present invention during color printing.

FIG. 2 in the drawings illustrates a representative, color-toner-usage“control” matrix 30 which describes one way of implementing the practiceof the present invention. Reference to this FIG. 2 matrix willimmediately inform those skilled in the relevant art not only how thisspecific matrix 30 establishes a workable set of page image elementfeatures to which toner usage rules may be assigned, but also clearlyindicates a representative pattern which can act as an instructionalbasis to those generally skilled in the art for establishing otherpatterns and matrices for the application of color-toner-usage rules.

Based on a matrix, such as matrix 30, several different mechanisms maybe invoked to print image elements in the desired “toner saving”fashion. For example, a system Administrator, or an IT manager, canconfigure a printer driver to provide appropriate printing options for auser. In such a case, a printer driver may be structures provide, via auser interface, options that enable a user individually to select itemsof (a) high (dense) information content, (b) low (sparse) informationcontent, and (c) unknown information content. These items could then beoutput automatically according to architecture of the relevanttoner-usage matrix. This approach is ideal for a printer driver based ona page description language such as PCL or PostScript in whichindividual elements are intrinsic to the page description language.

Returning attention now to FIG. 1, it is essentially block 22 in thatfigure, labeled “CHOOSE RULES”, which operates in relation to theformation and ultimate use (see arrowhead 22 a) of a toner-usage matrix,such as the one which has just been described with respect to FIG. 2. InFIG. 1, block 24, labeled “USER”, represents a system and methodologycondition wherein a user is enabled manually to choose a toner-usagematrix architecture, and thereby establish an appropriate set oftoner-usage rules that are to be employed with respect to differentkinds of color page image elements. Such “user enablement” mighttypically be offered in a situation where a color printer, or a computerand/or a document-creating application associated with such a printer,has not been programmed with a predetermined toner-usage matrix.Regarding manual user entry of toner-usage control information, FIGS. 3Aand 3B illustrate two, typical, printer-driver user interfaces by waysof which a user might choose and assign certain toner-usage rules withrespect to a particular document page which is to be color printed.

Block 26 in FIG. 1, labeled “PROGRAM”, represents a system andmethodology condition wherein someone, such as a system administrator,may establish an operative matrix, such as matrix 30, which isprogrammed and then controlled by a suitable software program installedin a color copier. Thus, whereas block 24 represents the opportunity foran individual user manually to establish toner-usage matrixarchitecture, and/or to determine user or group ID, block 26 representsthe condition where user selection is not permitted, or is overridden,and where automatically operative, pre-programming, as generallyoutlined earlier herein, is what controls such architecture. There are,of course, many conventional ways in which block 26 may be configured toimplement various forms of administrator control, and, accordingly,details of this block are not elaborated herein.

Block 28 in FIG. 1, labeled “LOCK”, represents the option for someone inauthority, again probably a system administrator, not only to choose afully software-controlled, and software-controlling, pre-determinedtoner-usage matrix, but also to lock that matrix against the possibilityof third party tampering or changing.

Taking a somewhat more specific look at toner-usage matrix 30 as shownin FIG. 2, and referring just to several of the there-labeled page imageelements which are referred to in FIG. 2 as “Values”, one can see thatLarge Text and Medium Text have been characterized as possessing high,or dense, information content, Photographs and Page Background have beencategorized as possessing low, or sparse, information content, and SmallText has been characterized as possessing unknown-density informationcontent. It is on the bases of these information densitycharacterizations that a functional color-printing division betweenthese several, different page image elements has been made which willcause respectively different toner-usage rules to be applied to each ofthem in the three different image density characteristics of dense,sparse and unknown.

As is shown in the matrix of FIG. 2, high (dense) information contentelements (Large Text, Medium Text, and Line Art) are to be output infull color (Default). Elements with low (sparse) information density(Photographic, Large Solid Color Areas and Page Background) will beoutput at 20% gray scale. Areas of unknown information density (SmallText, and Other) will be printed in full black. Some elements may not beprinted at all (No Print).

Reference in the column in FIG. 2 to the page image element categorygenerally identified as “Other” may apply to selected pagecharacteristics, such as the background-color, text-highlightingcharacteristic referred to above. Also, this column in FIG. 2, or anyother appropriate column in this figure, could, instead of (or inaddition to) listing the general category “Other”, specifically listparticular page characteristics of interest, e.g., “backgroundhighlighting”.

It is in this manner that selected page image elements become ultimatelyassigned, in one way or another, and as suggested earlier herein, fortreatment in accordance with the application of different toner-usagerules. And, it is this special behavior of the present invention thatwhich results in intelligent toner saving during color printing, inaccordance with practice of the invention.

Recognizing that the four vertically arranged blocks 22, 24, 26, 28which appear on the right side in FIG. 1 effectively describe severaldifferent ways in which the toner-usage rules become assigned for use inconjunction with different-character page image elements, typicalpractice of the present invention will now be described with and inconjunction with the five other blocks shown in FIG. 1.

When a color page is created for printing (block 12 labeled “INPUT PAGEIMAGE”), the image data for that page, in any suitable and conventionalmanner, is examined to identify different categories of the respectivepage image elements (block 14 labeled “EXAMINE AND IDENTIFY IMAGEELEMENTS”). With this determination made, the identified image elements,in accordance with practice of the invention, are respectivelyassociated with their appropriate toner-usage rules (block 22, arrowhead22 a, and block 16 which is labeled “ASSOCIATE ELEMENTS AND RULES”), andthese page image elements are then output (block 18 labeled “OUTPUTELEMENTS AND RULES”) to the marking engine (block 20 labeled “MARKINGENGINE”) in the relevant color printer. That marking engine is theneffectively instructed to apply the respective toner usage rules to thedifferent, identified page image elements, with the result that anoutput copied/printed page will be generated in a manner characterizedby the intelligent saving of color toner.

This very general description of the operation of the invention is fullyapplicable to all color-page printing behavior undertaken in a colorprinting environment that is operating utilizing the features of thepresent invention.

A very specific detailed illustration of the operation of the presentinvention is provided by the combination of FIGS. 4, 5 and 6 in thedrawings.

FIG. 4 illustrates a pre-printed illustration of color page 32 whichpossesses a number of different-category image elements, including text,photographs, line art, and background color. FIG. 4 may also be thoughtof as “describing” the relevant image data which has been created inorder to realize the page shown in this figure.

FIG. 5 illustrates an output-printed color presentation 34 of the pageshown in FIG. 4 following implementation of one form of the presentinvention with respect to which certain toner-usage rules have beenselected and applied.

FIG. 6, which includes a number of interconnected, internally labeledblocks 42-52, inclusive, provides a very self-explanatory disclosure ofhow the page (page image data) which is presented in FIG. 4 has beengenerated to produce the toner-saved page pictured in FIG. 5.

For example, initial “viewing” and analysis (block 42) of the underlyingcolor page data (32) has resulted in the identification of at least fourdifferent-category image elements, referred to in FIG. 6, block 44, as“Text 1”, “Photo 1”, “Line Art 1”, and Page Background, identified as“Pg Bkgnd”. These several page image elements identified in block 44 arelinked via an appropriate toner-usage matrix 46 to respectivelyassociated toner-usage rules in block 48, and are output via blocks 50,52 to a color-printer marking engine for the printing of page 34 as seenin FIG. 5. Such initial “viewing” will typically be performedelectronically in relation to the just-mentioned underlying image data.

Turning attention now to FIGS. 7 and 8, FIG. 7 shows at 54 a printingsystem, or environment including a computer 56, an MFP/printer 58, and aprint server 60 which is operatively interposed these two otherstructures. In this system, which implements the present invention, atoner-usage matrix, similar to previously described matrix 30, is shownat 62 to be resident in print server 60. This matrix (62) is accessed,during the execution of a page printing job, to furnish toner-usageinformation to the MFP/printer controller 64 which is structured toperform an image data analysis regarding the then subject page presentedfor printing. This controller, based on the mentioned, performed imagedata analysis, and on the accessible toner-usage data in matrix 62,controls operation of the associated print engine 66 in MFP/printer 58to generate a toner-saved output printed page.

FIG. 8 shows at 68 a printing system, or environment including acomputer 70, an MFP/printer 72, and an external document creatingapplication 74 which is operatively coupled the MFP/printer. In thissystem, which also implements the present invention, a toner-usagematrix, similar to previously described matrices 30, 62, is shown at 76to be resident within application 74. Matrix 76 is accessed, during theexecution of a page printing job, to furnish toner-usage information tothe controller 78 in MFP/printer, which controller is structured toperform an image data analysis regarding the then subject page presentedfor printing. This controller, based on the mentioned, performed imagedata analysis, and on the accessible toner-usage data in matrix 76,controls operation of the associated print engine 80 in MFP/printer 72to generate a toner-saved output printed page.

It will thus be apparent that a unique methodology, and a systemicorganization for implementing that methodology, have been illustratedand described herein for making intelligent use of color toner in acolor printing operation. Pages created for color printing in thecontext of implementation and practice of the present invention may becharacterized with a very wide variety of freely selectable page-imageelements, with these elements then being linked with freely chooseabletoner-usage rules aimed at implementing intelligent color printing withsignificant toner saving.

It will also be very apparent that the interconnected blocks shown inFIG. 1 may be read, from one point of view, and as has just above beendescribed, to illustrate the methodology of the present invention, andfrom another point of view, to illustrate also the systemic structure ofthe invention.

From a broadly-stated methodologic point of view, the invention can bedescribed as being a software-controlled method (10 in FIG. 1) forminimizing color toner use during printing of a color-page by a colorprinter. This method includes the steps of (a) examining the image datafor such a page to identify different, pre-copying, selected categoriesof page-contained image elements (block 12, 14 in FIG. 1), (b)thereafter associating, with identified different-category elements,specific, respective, pre-determined color-toner usage rules (blocks 16,22, and arrowhead 22 a in FIG. 1), and (c) following the step ofassociating, outputting the elements to the printer (block 18 in FIG. 1)along with instructions that the printer use, in the printing of suchelements, the correct, respectively associated color-toner usagerule(s).

The method of the invention further includes, generally speaking,pre-selecting the different categories of image elements on the basis ofrespectively related, pre-chosen, image content information densitycharacteristics of such elements, and establishing specific color-tonerusage rules which are to be associated with such different elementcategories.

From a broad structural and systemic point of view, the invention may beviewed as being software-controlled apparatus (10 in FIG. 1) forminimizing color toner usage during color-page printing by a colorprinter including (a) examining structure (block 14 in FIG. 1) forexamining the image data for a color page to identify differentpre-printing, selected categories of page-contained image elements, (b)associating structure (block 16 in FIG. 1) operatively connected to theexamining structure for associating, with identified, different-categoryimage elements, specific, respective, pre-determined color-toner usagerules, and (c) output structure (block 18 in FIG. 1) operativelyconnected to the associating structure for outputting the image elementsto a printer along with instructions that the printer use, in thecopying of the elements, the correct, respectively associatedcolor-toner usage rule(s).

Accordingly, while preferred and best-mode embodiments of, and mannersof practicing, the present invention, have been illustrated anddescribed herein, it is appreciated that variations and modificationsmay be made without departing from the spirit of the invention.

1. A software-controlled, page-by-page method for minimizing color tonerusage during printing of a color page by a color printer, where such acolor page potentially includes different page image elements, saidmethod comprising pre-selecting different categories of page imageelements on the basis of respectively related, pre-chosen,image-element-specific, image-content information densitycharacteristics, which characteristics are assigned to one of threedifferent levels identified as (a) dense, (b) sparse, and (c) unknown,and wherein the mentioned levels of information density characteristicsare determined utilizing at least one of certain thresholding factorsincluding (a) local contrast, and (b) image entropy, establishingspecific, different color-toner usage-level rules which are to beassociated individually and respectively with such differentimage-element categories, examining the image data for a color pagewhich is to be printed to identify therein the presences of differentones of the pre-selected image-element categories, associatingappropriately with each one of the identified, different categories ofsuch image elements, the specific, respective, established color-tonerusage rules, and following said associating, outputting theimage-elements to the printer along with instructions that the printeruse, in the specific, per-element printing of such image elements, thecorrect, respectively associated color-toner usage rule(s).
 2. Themethod of claim 1, wherein said pre-selecting is performed by at leastone of (a) user selection which, via the use of an appropriate userinterface, is directly input the color printing environment in apre-printing time frame, and (b) pre-established software programming,including administrator-control software programming, which isoperatively associated with that environment.
 3. The method of claim 2,wherein the mentioned pre-established software programming isselectively lockable.
 4. The method of claim 1, wherein the selectedcategories of page image elements include page-classification factors.5. A software-controlled, page-by-page method for minimizing color tonerusage during printing of a color page by a color printer, where such acolor page potentially includes different page image elements, saidmethod comprising pre-selecting different categories of page imageelements on the basis of respectively related, pre-chosen,image-element-specific, image-content information densitycharacteristics, which characteristics are assigned to one of threedifferent levels identified as (a) dense, (b) sparse, and (c) unknown,and wherein the mentioned levels of information density characteristicsare determined utilizing image-element object-analysis factors andnatures including (a) text, (b) graph, (c) line, (d) photograph, (e)color, (f) size, (g) local contrast, and (h) layering, establishingspecific, different color-toner usage-level rules which are to beassociated individually and respectively with such differentimage-element categories, examining the image data for a color pagewhich is to be printed to identify therein the presences of differentones of the pre-selected image-element-categories, associatingappropriately with each one of the identified, different categories ofsuch image elements, the specific, respective, established color-tonerusage rules, and following said associating, outputting theimage-elements to the printer along with instructions that the printeruse, in the specific, per-element printing of such image elements, thecorrect, respectively associated color-toner usage rule(s).
 6. Asoftware-controlled, page-by-page method for minimizing color tonerusage during printing of a color page by a color printer, where such acolor page potentially includes different page image elements, saidmethod comprising pre-selecting different categories of page imageelements on the basis of respectively related, pre-chosen,image-element-specific, image-content information densitycharacteristics, which characteristics are assigned to one of threedifferent levels identified as (a) dense, (b) sparse, and (c) unknown,and wherein the mentioned levels of information density characteristicsare determined utilizing page classification factors including (a) pagelayout, (b) halftone type and frequency, (c) page background complexity,and (d) relative page percentage of various object types, includingtext, photographs, charts, lines, and colors, establishing specific,different color-toner usage-level rules which are to be associatedindividually and respectively with such different image-elementcategories, examining the image data for a color page which is to beprinted to identify therein the presences of different ones of thepre-selected image-element-categories, associating appropriately witheach one of the identified, different categories of such image elements,the specific, respective, established color-toner usage rules, andfollowing said associating, outputting the image-elements to the printeralong with instructions that the printer use, in the specific,per-element printing of such image elements, the correct, respectivelyassociated color-toner usage rule(s).